At the present time, special problems exist in the construction industry and in the portion thereof relating to the pouring of concrete floors in warehouses and other large buildings. When such large buildings are intended to house computers, robots or other similar apparatus, flat or so-called super-flat floors are required to support these devices to insure their proper operation. The industry uses a device known as a vibrator screed for spreading and smoothing large areas of concrete since such a device helps cut costs by increasing the yardage of concrete which can be handled with minimal manpower.
A vibrator screed is particularly required in cases where a contractor purchases modern concrete having chemical additives which cause faster setting and hardening of the concrete.
A screed is essentially an elongated structure having a bottom bar which contacts and smooths the concrete. Screeds are adjustable in length and may be as long as 50 feet in length at the column lines. Thus, 20,000 square feet or more is an everyday routine pour. However, the smoothing of such large areas, particularly at the column lines, is a problem where one end of the screed bypasses one column and then the other end of the screed bypasses the column. Typically, when approaching the column on bulkheads, one end of the screed remains behind its column and the screed is tilted at about a 45.degree. angle to permit the other end of the screed to move around its column. When this is done, the one end of the screed is then pushed past the column and the screed is returned to its parallel position on the main bulkhead and moves on in the concrete smoothing operation.
In order to move the screed around opposed columns, an extra temporary form is installed at each column at the same elevation as the main bulkhead. This form is 2".times.4" or 2".times.6" depending on the thickness of the floor. Usually, the length of such a form is 6 feet or more. The problem is that when the screed slides on or rests on the temporary form, the weight of the screed is not supported by the form and this produces a depression or dip in the floor which cannot be smoothed out and alters the level of the floor. Clearly, this is not acceptable where flat or super-flat floors are required.